We have talked about this before, but I was wondering if anyone's opinion has matured or otherwise changed.
Should a crankcase be straightened with the lower pan in place, or not in place, and why?
I straightened them without the dip tray in place
If the lower cover makes that big of a difference once installed, then I'd say you've got a really messed up lower cover.
The pan will move with less effort with out the cover. Of course straighten the cover up flat and your good go.
Alot of pan door get over tightened
Get it flat as you can always use double gaskets
The pan cover (?) should be very flat around all edges. Beyond that? It really cannot be crooked. The crankcase/pan should be checked and straightened WITHOUT the lower cover bolted in place. The pan will give, flex, and reform, better without the lower cover in place. In fact, if the lower cover is in place? It in itself can prevent the pan from being properly straightened by preventing the crankcase pan from being pushed back into proper shape.
Once the crankcase has been straightened, and double checked, lining up and bolting the cover into place will act as a triple-check. If, for ANY reason, the properly flat edged, otherwise basically unbendable, cover cannot line up and be bolted into place? You done messed up big time somewhere. Pretty much, short of cutting and welding crooked (or using the wrong one?), the cover cannot be wrong.